Title : Bacillus sp. and its potential applications in Levan (prebiotic) synthesis using solid-waste valorization approach
Abstract:
Organic solid waste from agricultural industries, forestry residues, household garbage, vegetable and fruit markets, and other municipal waste are major sources of environmental contamination which not only affects the environment but also has adverse effects on population health. Waste valorization is a recent, efficient, and sustainable method of waste management. In this study, a potent thermophile (Bacillus sp.) was isolated from the thermal springs in India to hydrolyze and convert different organic solid wastes into an industrially important atypical biopolymer, levan (a well-known prebiotic). Morphological study using scanning electron microscopy (SEM), biochemical characterization, antibiotics sensitivity test, and antimicrobial and antioxidant potential of Bacillus sp. ATS 95 was checked. Maximum levansucrase activity and levan production from the strain ATS 95 were achieved using statistical methodologies. Various parameters like thermal stability, storage stability, higher sucrose and NaCl tolerance, bacterial growth, temperature, rpm, medium optimization including nitrogen, and carbon sources and their concentrations were analyzed. The effect of metal ions and organic solvents was also studied. The wide substrate affinity, high thermal, storage stability, and high salt, and sucrose tolerance ability of Bacillus sp. suggests its strong potential to degrade different solid wastes and valorize them into levan synthesis at an industrial scale. Further characterization study of levan synthesized from different wastes using X-ray diffraction (XRD), and thermogravimetric analysis (TGA) showed the amorphous and crystalline nature of the prebiotic production with very high thermal stability. This study is further aimed at the synthesis of levan-composite biofilm for coating raw as well as processed food items which will help in increasing their shelf life while maintaining texture and quality in an environment-friendly manner.
Keywords: Bacillus sp, Levan characterization, Solid waste valorization, Levan-composite biofilm, Food shelf life.
